The present invention relates to electrically operated valves such as solenoid operated valves employed for controlling water inlet to household appliances such as washing machines, dishwashers, and icemakers for refrigerators. Solenoid operated water inlet valves for household appliances typically utilize a plastic valve body and movable diaphragm type valving and are connected to a water supply by means of a compression type tube fitting in the case of small flow valves. Where relatively large flow is required, such as for washing machines, the valves typically of the pilot operated variety, and employ an electric coil disposed over a guide member with a movable armature therein for opening the pilot valve which creates a pressure differential across the diaphragm for effecting opening of the main valves. The water inlet valves of the aforesaid type may be connected directly to the household plumbing; and, the plumbing may be recessed in a wall of the building exposed to outside air temperatures. Where the plumbing is directed through an outside wall, problems are often encountered with freezing of the plumbing within the wall in regions insufficiently insulated to prevent sub-freezing temperatures from occurring in the plumbing during periods of non use. When ice forms in a localized region of the plumbing, the expansion caused during ice formation creates pressures in the plumbing which are substantially greater and often an order of magnitude greater than the normal pressures experienced in the water supply. These high pressures generated by ice formation in the household plumbing may cause bursting of the plastic bodied water inlet valve, which may be undetected at the time the burst occurs. Subsequently, upon the thawing of ice in the plumbing, flooding occurs through the appliance due to water flow through the burst in the inlet valve.
Thus it has been desired to provide a way or means of providing in a convenient, low-cost manner, high pressure relief for plastic bodied, electrically operated appliance water inlet valves to prevent rupture of the valves upon experiencing extraordinarily high pressures at the inlet such as the pressure experienced on the occasion of freezing in the plumbing structure to which the valve is connected for household use.